MetaLab is a research tool for aggregating across studies in the cognitive development literature. Currently, MetaLab contains996 effect sizes across meta-analyses in 15 domains of cognitive development, based on data from 265 papers collecting 16048 subjects. These studies can be used to obtain better estimates of effect sizes across different domains, methods, and ages. Using our power calculator, researchers can use these estimates to plan appropriate sample sizes for prospective studies. More generally, MetaLab can be used as a theoretical tool for exploring patterns in development across language acquisition domains.
Datasets tab.Statistical Approach tab.Field Specification tab.Contribute page.Please note that data and visualizations are under development at the moment (Winter 2017) and should not be taken as definitive.
This page provides an overview of all datasets in MetaLab at this moment. All datasets have more detailed descriptions available through their home pages.
All analyses on the site are conducted with the metafor package (Viechtbauer, 2010).
Effect size computation is handled by a script, compute_es.R.
Several pre-existing MAs deal with special cases, and these are listed in the script.
Except where noted, formulas are from Hedges & Olkin’s textbook.
The visualizations page uses a standard random effects meta-analysis as the default, but allows several other models (all available in the rma function of metafor).
For many analyses, the use of a multi-level approach (with grouping by paper) is useful, and may make a difference to results. We have not made this multi-level model the default, for two reasons. First, the approach will be unfamiliar to many users. Second, many common statistics are not implemented for this model, e.g. \(\tau^2\) and the test for funnel-plot asymmetry.
This page gives the full specification for each field in the metalab dataset, including: required fields (which must be included for every MA), optional fields (which are only used for some MAs), and derived fields (which are computed by the site).